Releasable ski binding

ABSTRACT

A safety binding for use with snow skis and boots consisting of two separable but coacting parts comprising a sole-mounted movable mechanism and a ski-mounted relatively rigid fixed plate or member. The plate or member and movable mechanism each engage cooperating elements of the other. In one embodiment, the movable mechanism comprises a lever mechanism. The lever mechanism comprises a movable longitudinally-extending spring-biased connecting rod or strip having a wedge-shaped end which mates freely with conforming surfaces of a pivotable lever. In this embodiment, as the strip is moved, the lever is caused to pivot so as to releasably engage the fixed plate for providing a releasable connection between the plate and the lever mechanism. In another embodiment, a rotating lever mechanism is provided for engaging a ski-mounted fixed plate or member within a cavity in a boot sole. The cavity extends to the rear of the boot sole to permit longitudinal release and separation without heel lifting movement of the boot relative to the ski. In both embodiments, the binding assembly resists all degrees of relative movement between the ski boot and ski without the necessity of a toe restraining device and, further, permits separation in the longitudinal direction without heel lifting movement. In these embodiments, wherein the engaging elements are wholly within the interior edges of the boot sole, there is further provided a spring biased, movable plate assembly which prevents the impaction of ice and snow in the movable parts.

United States Patent 1191 Spademan l l RELEASABLE SKI BINDING Richard G. Spademan. 933 Addison Ave., Palo Alto. Calif. 94301 122} Filed: Jan. 29. 1974 211 App]. N0.;437.719

Related U.S. Application Data [63] Continuatiomin-part of Ser. No. 136.82fi. April 23. 1971. abandoned. which is a continuution'impart of Ser. No. 868.271. Oct. 7. 1969. Pat, No. 3.606.370. which is a continuation-impart of Ser. No. 769.682. Octv 22. 1968. abandoned.

[76] Inventor:

[52] U.S. Cl 280/.35 R [51 I Int. Cl. A631: 9/08 [581 Field ofSearch ..280/] 1.35 D. 11.35 K

280/1 1.35 15.11.35 A,1l.35 (5.11.35 Y. 280/1135 R,ll.35N. 11.35 M.ll.35 B;

Primary Examiner-Leo Friaglia Assistant E.\amirwrMilton L. Smith 157] ABSTRACT A safety binding for use with snow skis and boots con- 1 June 24, 1975 sisting of two separable but coacting parts comprising a sole-mounted movable mechanism and a skimounted relatively rigid fixed plate or member. The plate or member and movable mechanism each engage cooperating elements of the other. In one embodiment. the movable mechanism comprises a lever mechanism. The lever mechanism comprises a movable longitudinally-extending spring-biased connecting rod or strip having a wedge-shaped end which mates freely with conforming surfaces of a pivotable lever. In this embodiment. as the strip is moved. the lever is caused to pivot so as to releasably engage the fixed plate for providing a releasable connection between the plate and the lever mechanism. In another embodiment, a rotating lever mechanism is provided for engaging a ski-mounted fixed plate or member within a cavity in a boot sole. The cavity extends to the rear of the boot sole to permit longitudinal release and separation without heel lifting movement of the boot relative to the ski. In both embodiments. the binding assembly resists all degrees of relative movement between the ski boot and ski without the necessity of a toe restraining device and. further, permits separation in the longitudinal direction without heel lifting movement. In these embodiments. wherein the engaging elements are wholly within the interior edges of the boot sole. there is further provided a spring biased. movable plate assembly which prevents the impaction of ice and snow in the movable parts.

19 Claims, 14 Drawing Figures RELEASABLE SKI BINDING BACKGROUND OF THE INVENTION This is a continuation-in-part of copending application Ser. No. 136,826, filed Apr. 23, I97I. entitled Releasable Ski Binding, and now abandoned which is a continuation-in-part of copending application Ser. No. 868,27l, filed Oct. 7. 1969, entitled Safety Binding Mechanism,- now US. Pat. No. 3,606,370, which is a continuation-in-part of application Scr. No. 769.682, filed Oct. 22, I968, entitled Safety Binding Mechanism," now abandoned.

The present invention relates in general to safety bindings of the type disclosed in U.S. Pat. 327L040, in which there is described and illustrated a mechanism for releasably securing a ski boot to a ski, which releasably resists all degrees of movement of the ski boot relative to the ski namely, longitudinal, lateral, twisting and heel-lifting movement without requiring the use of a toe fastening device. Such a construction not only reduces costs in view of resulting simplification and a reduction in the number of parts, but also reduces the risk of serious leg injury. as frequently occurs when the toe of a boot encounters an impediment to forward movement during a downhill fall.

In implementing the structures disclosed in the above patent. however, it was found that good mechanical stability is often difficult to achieve in view of the close spacing of the various contacting surfaces used to resist the different degrees of movement of the ski boot. In this regard it was determined that bindings were frequently misaligned during installation so as to adversely affect their function in operation. It was also determined that, with bindings having the engaging elements interior of the edges of the boot. the mechanisms were subject to clogging by ice and snow impactionv SUMMARY OF THE INVENTION In accordance with the invention there is provided several improved and simplified bindings comprising whollyintegrated spring-biased mechanisms which coact with and releasably engage a relatively rigid fixed plate or member mounted on a ski for providing a much more mechanically stable ski binding than heretofore available and one in which the moving parts are able to be mounted on or within the sole of a ski boot in the same wholly integrated fashion with a much more aesthetically pleasing appearance and reliable operation. Mounting the majority of the binding on or in the sole of a skiers boot, it is determined, further re duces the cost of equipment by permitting the same boot to be used with a variety of skis without the need for additional expensive bindings or time-consuming and difficult installations which have often resulted in misalignment of the critical parts.

Accordingly, in one embodiment a principal feature of the invention is a lever which is pivotably mounted adjacent a longitudinally-extending connecting strip which is spring-biased at one end and provided with a wedge-shaped surface on the other. The wedge-shaped surface on the connecting strip mates with and is maintained in sliding contact with a conforming wedgeshaped surface on the lever. As the connecting stip is moved, an exterior edge of the lever is caused to engage a corresponding part of a fixed plate or member fixed to the ski.

In another embodiment. a fixed ski'mounted plate or member is provided with a beveled mating surface which engages a correspondingly beveled plate coupled to a spring-biased lever which rotates on an axis transverse the ski and boot. The engagement of the boot and ski occurs in a cavity in the sole of the boot. To prevent an impaction of ice and snow in the cavity during walk ing and a fall, means are provided to enclose the cavity.

A principal object achieved with the invention, as will become more apparent from the detailed description below, is a releasable ski binding having improved mechanical stability, which can be mounted in or on the sole of a ski boot.

Another object is a binding free of frequent misalignment during installation.

A third object is a binding which permits installation of the majority of the hardware in or on the sole of a boot thereby reducing the time, cost and inconvenience of mounting considerable hardware on the skis. thus permitting the use of a variety of skis without the need for additional expensive bindings or difficult adjustments.

DESCRIPTION OF THE DRAWINGS The various other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description, taken in connection with the accompanying drawing, wherein:

FIG. I is a side elevational view of a ski boot affixed to a ski by a safety binding in accordance with one embodiment of the present invention;

FIG. 2 is a bottom plan view of the ski mounted plate, and safety binding of FIG. I, the ski having been omitted for clarity of illustration;

FIG. 3 is a front elevational view of the ski plate and safety binding of FIG. 1;

FIG. 4 is a top plan view of the ski-mounted plate and safety binding of FIG. I, with the boot omitted for clarity of illustration;

FIG. 5 is a bottom plan view of the ski-mounted plate and safety binding of FIG. 4, shown as disengaged due to the twisting force of the ski boot;

FIG. 6 is a side elevational view of the ski boot, ski and safety binding of FIG. 1, shown as disengaged due to the heel-lifting force of the ski boot;

FIG. 7 is a bottom plan view of a ski boot in accordance with the present invention;

FIG. 7A is an elevation view of the heel portion of the boot of FIG. 7 on a ski;

FIG. 8 is a bottom plan view of the boot of FIG. 7 with the sliding bottom plate removed and the heel door in a raised position;

FIG. 9 is a partially cut-away section in elevation of the heel section of the boot of FIG. 7 on a ski.

FIG. I0 is a side elevation view of a ski boot affixed to a ski by a safety binding in accordance with still another embodiment of the present invention;

FIG. I1 is a plan view of the binding of FIG. 10;

FIG. 12 is a rear elevational view of the ski boot. ski and safety binding of FIG. I];

FIG. [2A is an enlarged view of the knob and spring assembly of FIG. 12.

DETAILED DESCRIPTION Referring to FIGS. 1-6, there is shown one embodiment of the present invention wherein the moving parts comprising a spring-biased lever mechanism I are mounted on or in the sole 2 of a ski boot 3. A plate 4 enclosing lever mechanism 1 is mounted in the bottom of the sole 2 of ski boot 3 and is provided to overlay a plate or member 49 secured to the top of a ski 5. Plate 49 comprises a pair of clamping tabs 50 which are engaged by lever mechanism 1 for releasably resisting longitudinal lateral, twisting and heel-lifting movement of boot 3 relative to ski 5. Clamping tabs 50 are, in general, located to the rear of the point of application of heel-lifting force on the boot, which point is to the rear of the boot toe by an amount which varies with the flexibility of the sole. Typically. with usual boot construc tion, this point is adjacent or coincident with the ball of the skiers foot.

The ski plate 49 has a plurality of holes 49' for purposes of affixing the same as by screws to the upper sur' face of ski S. The ends of plate 49 project perpendicularly outwardly from the sides of the boot sole and comprise the vertically rising clamping tabs 50, which are generally symmetrical with respect to the transverse axis of boot 3.

Each clamping tab 50 is fixedly mounted in an up standing relationship with respect to a pair of lever or plate arms 12 forming a part of lever mechanism 1. Each lever or arm 12 is positioned within the ski plate 4 and is pivotedly supported on said plate in parallel relationship thereto by means of a vertical rivet or pin 13. The arms 12 are driven for pivoted motion about the pins 13, thereby moving inwardly or outwardly out of and into engagement with clamping tabs 50 by a connecting plate or strip 51 attached at one end to a spring-biased release mechanism 7. About the periphery of the boot plate 4 there is provided an upwardly extending edge 4 which supports the surface of plate 4 a sufficient distance from the sole of boot 3 to pro' vide space for the clamping levers l2 and connecting strip 51.

The connecting strip 51 has two upstanding members 21 extending upward from the rearward end thereof through a slot 22 in the boot plate 4. The members 21 fixedly support a transverse pin 23 therebetween. A rod 24 of the release mechanism 7 is pivotedly mounted for rotation about the pin 23. A pair of upstanding members 25 extend upward from the boot plate 4 with the connecting strip members 21 being disposed inwardly of, and parallel to, the members 25. An adjustment nut 26 is threaded to the rear end of the rod 24 and retains a washer 27 slidably engaged against the rear surface of the ski plate upstanding members 25, via a compression spring 28 retained between the adjustment nut 26 and the washer 27. The surface of rod 24 can be provided with graduation markings of dots, crosses or numbers, not shown, which when lined up with corre sponding indicia 60 on nut 26 provide a measure of the compression applied to spring 28. As can be seen in FIGS. 1 and 6, the rear edges of the members 25 are curved and serve as a guide for manually pivoting the rod 24 from the clamped position (shown in full lines in FIG. 1) to the released position (shown in phantom lines in FIG. 1).

As seen in FIG. 4, the clamping arms 12 extend through openings 31 in the upwardly extending edge 4 of the ski plate 4. The maximum outward rotation of the arms 12 about the pins 13 is limited by the engagement of the arms 12 against the edge 4' at the rearward end of the openings 31. Inwardly directed tongue portions 32 are formed in the arms 12 so as to stabilize arms 12 between the plate 4 and the boot sole 3 even when the arms 12 are in this maximum outward position. Each clamping arm 12 further has an outwardly inclined wedge surface 58 formed therein which conforms with a complementary wedge surface 52 formed in the forward end of the connecting strip 5]. Bosses 35 and 36 are formed in the upper surface of the plate 4 and project through respective slots 37 and 38 in the connecting strip 51 to thereby form an alignment guide for longitudinal movement ofthc strip 51 relative to the plate 4. The compression spring 28, acting through pin 23 and upstanding members 21, biases the connecting surfaces 52 against the clamping arm surfaces 58, thereby biasing the clamping arms 12 outwardly due to the wcdging action of the surfaces 58 and 52.

The configuration of the clamping tabs 50 on ski plate 49 is seen in FIGS. 3 and 5. As seen in FIG. 3, the tabs 50 are formed with an inwardly directed are such that the portion 41 of the tabs 50 above the boot plate 4 is upwardly and outwardly directed and the portion 42 which is engaged by the arms 12 within boot plate 4 is upwardly and inwardly directed. As seen in FIG. 5, the outward edges of the tabs 50 are formed with inwardly curved convex male portions 43, symmetrically disposed with respect to a transverse axis of the ski 5, which mate in male-female relationship with a pair of concave portions 60 on arms 12. The two engaging sur faces 43 are tangentially joined by a generally straight surface 44.

In operation, when the skier desires to mount the ski S, the release mechanism 7 is unclamped by rotating the rod 24 counterclockwise as shown by the phantom lines in FIG. 1. The wedge surfaces 52 0f the connecting strip 51 are thereby disengaged from the wedge surfaces 58 of the clamping arms 12, whereby the arms 12 are free to pivot inwardly about the pins 13. The boot 3 is then placed with the female surfaces 60 of the arms 12 engaged inside the upward portions 41 of the clamping tabs 50. The outwardly angled configuration of the tab portions 41 facilitates such insertion of the arms 12. The boot is then placed to rest with the sole 2 on the ski plate 49. Next the release mechanism 7 is activated by rotating the rod 24 clockwise overcenter as shown by the solid lines in FIG. 1, whereupon the spring 28 urges the wedge surfaces 52 against the wedge surfaces 58 bringing the arms 12 into engagement with clamping tabs 50 as seen in FIGS. 1, 2, 3 and 4. A clip or the like (not shown) may be inserted through holes 25 in the upstanding members 25 so that accidental upward movement of the rod 24 is prevented. The ski boot 3 then remains fixed to the ski 5 either until a voluntary release is accomplished by manual unclamping of the release mechanism 7, or until an impending fall condition causes sufficient force to be transmitted to the safety binding for effecting safety release in a manner which will now be described in detail.

Under the engaged condition, shown in FIGS. 1, 2, 3, and 4, longitudinal, lateral and twisting movement of the boot 3 is resisted by the contacting of the female surfaces 60 of the arms 12 with the male surfaces 43 of the clamping tabs 50. Further, heel-lifting movement is resisted by virtue of the fact that any lifting of the boot plate 4 along the inwardly included surfaces 42 of the clamping tabs 50 increases the friction between the plate and said inclined surfaces. When excessive force is transmitted by the boot to the binding, the clamping arms 12 transmit sufficient forwardly-directed force to the connecting strip 51. via wedge surfaces 58 and 52, to overcome the bias of the compression spring 28. This biasing force can be adjusted for the desired release conditions by suitable positioning ofthe adjusting nut 26. Moreover. it should be noted that the amount of longitudinal force required for release is determined by the ratio of the length of the curved mating surfaces 43 of the clamping tabs 50 to the length of the straight surface 44 of said tabs. said force varying directly with the magnitude of said ratio.

When excessive twisting force is transmitted by the boot to the binding. the female surfaces 60 of the arms 12 cam over the male surfaces 43 of the clamping tabs 50, against the bias of the spring 28, whereby the boot plate becomes free of the ski as shown in FIG. 5. When excessive heel-lifting force is transmitted by the boot to the binding. the surfaces 60 cam over the inwardly directed surfaces 42 of the clamping tabs 50 also against the bias of the spring 28, whereby the boot plate becomes free of the ski as shown in FIG. 6.

Referring to FIGS. 12, there is shown a partial view of the heel portion of a ski boot of an alternative embodiment of the present invention comprising an upper 201 and a sole 202 secured to a ski 203 by means of a releasable binding assembly designated generally as 204. Releasable binding assembly 204 comprises a sole-mounted movable assembly 220 and a skimounted plate or retaining member 205. Plate 205 is provided with an arcuate beveled surface 206 which mates with and is engaged by an arcuate beveled surface 207 on a pivotable plate 216 forming a part of sole-mounted assembly 220. The surface 206 of ski plate 205 has a broader upper than lower edge as illustrated in FIGS. 10, 11 such that the surface 207 of plate 216 provides interlocking engagement of the boot to the ski when the releasable binding assembly 204 is actuated to the clamping position. Ski plate 205 is secured to the top of ski 203 with screws 213 or the like.

Referring to the sole-mounted movable assembly 220, pivotable plate 216 is attached to and forms a part of a rod 208. Plate 216 and rod 208 rotate within bushings 219 or the like secured in the sides of the boot sole 202. A coil spring 209 is secured at one end to rod 208 and by means of an extension 213 to a knurled adjustment knob 210 rotatably mounted to said rod 208 at the other end. As shown in FIG. 12A, knob 210 is provided with a spring-biased button 212 that fits a plurality of complementary holding indentations 214 in an apcrtured plate 221 mounted on the side of the ski boot sole 202. Plate 221 is in the shape of a washer for providing clearance for extension 213 of spring 209 when knob 210 is rotated and serves to hold knob 210 from freely rotating after an adjustment is made. By rotating the knob 210, the button 212 will fall successively into indentations 214 in plate 221 thereby regulating the tension on coil 209 and the amount of force required to effect a release of binding 204 under fall conditions. Knob 210 is held against the indented plate 221 by the tension of the coil spring.

Referring to FIGS. 10 and 11, the forward edge of ski plate 205 is provided with an arcuate beveled indentation 217 that interlocks in a male-female relationship with a corresponding retaining means comprising an arcuate beveled nipple 218 located in the ski boot sole 202 for retaining the ski boot on the ski such that longitudinal. lateral. twisting and heellifting movement of said ski boot relative to said ski is resisted except in a safety release. as will be apparent.

Voluntary release and locking is effected between the boot plate 216 and the ski plate 205 by activation of a lever 211 attached to the end of rod 208 opposite knurled knob 210. Lever 211 may be activated by hand or with a ski pole inserted in a depression 215 to pivot plate 216 away from ski plate 5 when depressed.

The ski boot sole 202 is appropriately slotted. bored and otherwise formed to accommodate the various parts of the ski boot assembly 204. Additionally, a central rectangular section 222, shown by dashed lines in the bottom of the ski boot sole 202, is cut out. The cutout extends from a line along the forward base of nipple 218 which is engaged by ski plate 205 rearwardly through the heel portion of sole 202. Thus. upon forward release of the boot from the ski, the rear portion of the boot does not form an obstruction to impede forward movement of the boot parallel to the surface of the ski. It is apparent that in a potential injurysustaining fall the force of the fall overcomes the tension of the coil spring 209 such that the boot plate 216 pivots backward and upward allowing disengagement of the ski plate 205 from the boot plate 216 and nipple 218.

Since a conventional toepiece is not required with the binding of the present invention. binding assembly 204 may be located at any point forward of the heel of the boot and rearwardly of the point of application of heel-lifting force.

To prevent clogging of the assembly 204 by the impaction of ice and snow during normal walking or after a fall. there is provided, as shown in FIGS. 7-9, a cover plate and door assembly in a modified form of the boot and binding assemblies of FIGS. 10-12A comprising a spring biased cover plate 230 and a spring-biased heel door 231 for enclosing the cutout 222.

Plate 230 is slidably fitted substantially flush with the surface of sole 202 in a shallow recess 232 which extends substantially the full length of the sole. Forward of cavity 222, there is provided another cavity 235. The length of cavity 235 is approximately equal to the length of cavity 222. Extending from the forward edge of cavity 235 is a bore 236. Bore 236 may be of any cross-section, but is typically cylindrical. Centrally mounted within cavity 235 and bore 236 is a springretaining rod 237. Loosely fitted about rod 237 is a spring 238 which in minimum compression extends from the forward end of bore 236 to a plate block 239 slidably fitted on rod 237. Plate 230 is secured as by a screw 240 to the plate block 239. As will be apparent, as plate 230 is moved forward, spring 238 is compressed into bore 236 for returning the plate 230 to its closed position as shown in FIG. 7 when the opening force is removed.

The spring-biased heel door 231 is pivotably mounted at the rearward end of cavity 222 and is fitted in flush relationship thereto in a shouldered recess 245 and above plate 230. As so constructed, plate 230 prevents inadvertent opening of the door 231 during normal walking. To open the door 231, there extends perpendicular thereto a member 246 in which, at its outer end. there is provided a hole 247. A spring member 248 is fixed to the boot sole and overlaps the door 231 in sliding relationship for biasing the door in a closed position.

Referring to FIG. 9, when ski plate 205 is not engaged by pivotablc plate 216, plate 216 is pivoted by spring 209 from its normal engaging position, shown in phantom lines, to a position abutting the roof of cavity 222, as shown in solid lines. In this position. a clearance space for ski plate 205 is provided between plate 216 and plate 230.

In order to enter the ski boot assembly 204, rear door 231 is opened as by the insertion of the tip of a ski pole in hole 247 followed by a slight upward and rearward motion of the tip. Once the door is opened sufficiently to clear the ski plate 205, the sliding plate 230 is urged forward by the plate 205 upon rearward movement of the boot relative to the ski as illustrated by the arrows. Alternatively, the exposed rear position of plate 230 below door 231, as seen in FIG. 7A, permits entry of the cavity 222 and assembly 204 by the ski plate 205 without opening the door 231. This is accomplished by raising the heel slightly and pushing on the exposed rear portion of plate 230 by an upper forward margin of the plate 205 until the door 231 is cleared, at which point the boot heel may be lowered to the ski and the entry completed. If opened consistently in this manner, member 246, extending from door 231, may be eliminated.

Entry of the binding is completed by continuing the rearward movement of the boot relative to the ski until plate 205 abuts nipple 218 at the forward end of cavity 222. Lever 211 is then rotated counterclockwise until plate 216 comes into contact with the upper surface of plate 205. Further rotation of lever 211 will cause the heel of the boot to rise slightly from the ski until plate 216 clears plate 205. When plate 216 clears plate 205, the boot will drop to the ski. Lever 211 is then released permitting spring 209 to urge plate 216 into releasable engagement with plate 205.

During a forward fall involving sufficient force to effect release, plate 216 is pivoted by plate 205 counterclockwise against the tension of spring 209. Ski plate 205 is thereafter free to move rearwardly through cavity 222 and past door 231 without heel-lifting movement of the boot relative to the ski.

During walking or upon any release of the boot and ski, it is now apparent that plate 230 and door 231 will automatically enclose cavity 222 under the influence of their respective spring members, thus preventing the accumulation of snow and ice in the cavity.

It is understood that various modifications of the bindings as illustrated may be made by one skilled in the art without departing from the spirit and scope of the present invention. Accordingly, it is intended that the invention not be limited to the enbodiments described but, rather. be construed as broadly as the claims hereinafter provided will allow.

What is claimed is:

l. A releasable ski binding for releasably securing a ski boot to a ski comprising:

a first engaging means located on one of said ski boot and said ski;

a second engaging means located on the other of said ski boot and said ski;

a third means coupled to said first engaging means for resiliently biasing said first engaging means into releasable engagement with said second engaging means for releasably securing said ski boot to said ski at a point interior of the side and rear edges of said ski boot; and

a fourth means for permitting upon disengagement of said first and said second engaging means a separation of said ski boot from said ski without requiring heel lifting movement of said ski boot relative to said ski.

2. A releasable ski binding according to claim 1 wherein said resilient biasing means comprises:

a movable rod extending transverse the longitudinal axis of said ski boot. said rod having an intermediate section on which is located said first engaging means;

a spring adjustment member; and

a spring member, said spring member having a first end attached to said rod and a second end attached to said spring adjustment member for adjusting the magnitude of bias urging said first engaging means into said releasable engagement with said second engaging means.

3. A releasable ski binding for releasably securing a ski boot to a ski comprising:

a retaining member, said retaining member having a first mating surface;

a movable assembly, said assembly having a second mating surface;

a means coupled to said movable assembly for resiliently urging said second mating surface into releasable engagement with said first mating surface, and wherein both said first and said second mating surfaces are located interiorly of the side and rear edges of said boot sole, and said movable assembly and said retaining member have means cooperating with said first and said second mating surfaces for releasably securing said ski boot to said ski; and

a means for permitting upon disengagement of said first and said second mating surfaces a separation of said ski boot from said ski without requiring heel lifting movement of said ski boot relative to said ski.

4. A releasable ski binding according to claim 3 wherein said cooperating means comprises:

a third mating surface on said retaining member;

a retaining means located in a sole portion of said ski boot, said retaining means having a fourth mating surface and wherein said movable assembly further comprises:

a means for urging said third and said fourth mating surfaces into releasable engagement.

5. A releasable ski binding according to claim 4 wherein said first, said second, said third and said fourth mating surfaces comprise arcuate beveled surfaces.

6. A releasable ski binding according to claim 3 further comprising:

a means for mounting said retaining member on a ski;

and

a means for mounting said movable assembly in a ski boot sole, and wherein said first and said third mating surfaces are on opposing faces of said retaining member, said second mating surface is on said movable assembly and said fourth mating surface is on said retaining means.

7. A releasable ski binding according to claim 6 wherein said means for permitting disengagement 01 said first and said second mating surfaces and separation of said ski boot from said ski without requiring heel lifting movement of said boot relative to said ski during separation comprises a cutout in said ski boot sole 8. A releasable ski binding according to claim 7 wherein said means for permitting separation of said ski boot from said ski without requiring heel lifting movement comprises:

a means for moving said movable assembly out of the path of said retaining member during separation.

9. A releasable ski binding according to claim 8 wherein said retaining means comprises a portion of the forward surface of said cutout in said ski boot sole and said fourth mating surface comprises the surface of said portion facing said retaining member.

10. A releasable ski binding for releasably securing a ski boot to a ski comprising:

a ski member mounted on a ski;

a boot member mounted in a cavity in the sole of a ski boot;

a means for releasably engaging said ski and said boot members in said cavity, said means including means for disengaging said ski and said boot members involuntarily; and

a means for automatically enclosing said cavity when said ski and said boot members are disengaged involuntarily, said enclosing means serving to prevent the impaction of unwanted debris in said cavity, which would impair said engaging and said disengaging of said ski and said boot members.

ll. A releasable ski binding according to claim 10 wherein said means for enclosing said cavity comprises:

a first member movably mounted in said sole of said ski boot; and

a means for moving said first member from a first position to a second position for uncovering said cavity when said ski and said boot members are engaged, and from said second position to said first position for covering said cavity when said ski and said boot members are disengaged.

12. A releasable ski binding according to claim 11 further comprising a means for permitting, upon disengagement of said ski and said boot members, a separation of said ski and said ski boot without heel-lifting movement of said boot relative to said ski.

13. A releasable ski binding according to claim 12 wherein said means for permitting separation of said ski and said ski boot without heel-lifting movement comprises an extension of said cavity to the exterior of said sole of said ski boot and further wherein said enclosing means includes means for covering and uncovering said extension.

14. A releasable ski binding according to claim 13 wherein said means for enclosing said extension of said cavity further comprises:

a second member movably mounted in said sole of said ski boot; and

a means for moving said second member from a first position to a second position for permitting separation of said ski boot from said ski without heellifting movement of said ski boot relative to said ski, and from said second position to said first position upon said separation for enclosing said extension of said cavity.

15. A releasable ski binding according to claim 14 wherein said first member is slidably mounted in a recess in the bottom surface of said ski boot sole and said second member is pivotably mounted in a recess in the rear surface of said ski boot sole substantially normal to said first member.

16. A releasable ski binding according to claim 15 wherein said second member is mounted interior of and substantially flush with said first member for preventing involuntary movement of said second member after separation of said ski boot from said ski.

17. A releasable ski binding according to claim 16 wherein said means for moving said first and said second members comprises first and second spring members.

18. A releasable ski binding according to claim 17 wherein said means for moving said first member further comprises:

a rod mounted in a recess in said sole of said ski boot;

a means for retaining said first spring member on said rod; and

a means slidably fitted on said rod for coupling said first spring member to said first member for moving said first member from an open position to a closed position upon disengagement of said ski and said boot members and separation of said ski and said boot.

19. A releasable ski binding according to claim 18 wherein said means for moving said second member further comprises a means for coupling said second spring member to said second member for resiliently biasing said second member in a closed position. 

1. A releasable ski binding for releasably securing a ski boot to a ski comprising: a first engaging means located on one of said ski boot and said ski; a second engaging means located on the other of said ski boot and said ski; a third means coupled to said first engaging means for resiliently biasing said first engaging means into releasable engagement with said second engaging means for releasably securing said ski boot to said ski at a point interior of the side and rear edges of said ski boot; and a fourth means for permitting upon disengagement of said first and said second engaging means a separation of said ski boot from said ski without requiring heel lifting movement of said ski boot relative to said ski.
 2. A releasable ski binding according to claim 1 wherein said resilient biasing means comprises: a movable rod extending transverse the longitudinal axis of said ski boot, said rod having an intermediate section on which is located said first engaging means; a spring adjustment member; and a spring member, said spring member having a first end attached to said rod and a second end attached to said spring adjustment member for adjusting the magnitude of bias urging said first engaging means into said releasable engagement with said second engaging means.
 3. A releasable ski binding for releasably securing a ski boot to a ski comprising: a retaining member, said retaining member having a first mating surface; a movable assembly, said assembly having a second mating surface; a means coupled to said movable assembly for resiliently urging said second mating surface into releasable engagement with said first mating surface, and wherein both said first and said second mating surfaces are located interiorly of the side and rear edges of said boot sole, and said movable assembly and said retaining member have means cooperating with said first and said second mating surfaces for releasably securing said ski boot to said ski; and a means for permitting upon disengagement of said first and said second mating surfaces a separation of said ski boot from said ski without requiring heel lifting movement of said ski boot relative to said ski.
 4. A releasable ski binding according to claim 3 wherein said cooperating means comprises: a third mating surface on said retaining member; a retaining means located in a sole portion of said ski boot, said retaining means having a fourth mating surface and wherein said movable assembLy further comprises: a means for urging said third and said fourth mating surfaces into releasable engagement.
 5. A releasable ski binding according to claim 4 wherein said first, said second, said third and said fourth mating surfaces comprise arcuate beveled surfaces.
 6. A releasable ski binding according to claim 3 further comprising: a means for mounting said retaining member on a ski; and a means for mounting said movable assembly in a ski boot sole, and wherein said first and said third mating surfaces are on opposing faces of said retaining member, said second mating surface is on said movable assembly and said fourth mating surface is on said retaining means.
 7. A releasable ski binding according to claim 6 wherein said means for permitting disengagement of said first and said second mating surfaces and separation of said ski boot from said ski without requiring heel lifting movement of said boot relative to said ski during separation comprises a cutout in said ski boot sole.
 8. A releasable ski binding according to claim 7 wherein said means for permitting separation of said ski boot from said ski without requiring heel lifting movement comprises: a means for moving said movable assembly out of the path of said retaining member during separation.
 9. A releasable ski binding according to claim 8 wherein said retaining means comprises a portion of the forward surface of said cutout in said ski boot sole and said fourth mating surface comprises the surface of said portion facing said retaining member.
 10. A releasable ski binding for releasably securing a ski boot to a ski comprising: a ski member mounted on a ski; a boot member mounted in a cavity in the sole of a ski boot; a means for releasably engaging said ski and said boot members in said cavity, said means including means for disengaging said ski and said boot members involuntarily; and a means for automatically enclosing said cavity when said ski and said boot members are disengaged involuntarily, said enclosing means serving to prevent the impaction of unwanted debris in said cavity, which would impair said engaging and said disengaging of said ski and said boot members.
 11. A releasable ski binding according to claim 10 wherein said means for enclosing said cavity comprises: a first member movably mounted in said sole of said ski boot; and a means for moving said first member from a first position to a second position for uncovering said cavity when said ski and said boot members are engaged, and from said second position to said first position for covering said cavity when said ski and said boot members are disengaged.
 12. A releasable ski binding according to claim 11 further comprising a means for permitting, upon disengagement of said ski and said boot members, a separation of said ski and said ski boot without heel-lifting movement of said boot relative to said ski.
 13. A releasable ski binding according to claim 12 wherein said means for permitting separation of said ski and said ski boot without heel-lifting movement comprises an extension of said cavity to the exterior of said sole of said ski boot and further wherein said enclosing means includes means for covering and uncovering said extension.
 14. A releasable ski binding according to claim 13 wherein said means for enclosing said extension of said cavity further comprises: a second member movably mounted in said sole of said ski boot; and a means for moving said second member from a first position to a second position for permitting separation of said ski boot from said ski without heel-lifting movement of said ski boot relative to said ski, and from said second position to said first position upon said separation for enclosing said extension of said cavity.
 15. A releasable ski binding according to claim 14 wherein said first member is slidably mounted in a recess in the bottom surface of said ski boot sole and said second member is pivotably mounted in A recess in the rear surface of said ski boot sole substantially normal to said first member.
 16. A releasable ski binding according to claim 15 wherein said second member is mounted interior of and substantially flush with said first member for preventing involuntary movement of said second member after separation of said ski boot from said ski.
 17. A releasable ski binding according to claim 16 wherein said means for moving said first and said second members comprises first and second spring members.
 18. A releasable ski binding according to claim 17 wherein said means for moving said first member further comprises: a rod mounted in a recess in said sole of said ski boot; a means for retaining said first spring member on said rod; and a means slidably fitted on said rod for coupling said first spring member to said first member for moving said first member from an open position to a closed position upon disengagement of said ski and said boot members and separation of said ski and said boot.
 19. A releasable ski binding according to claim 18 wherein said means for moving said second member further comprises a means for coupling said second spring member to said second member for resiliently biasing said second member in a closed position. 